driving a serial synthesizer through speech-dispatcher

[Samuel Thibault]

Gregory Nowak, le jeu. 06 févr. 2020 17:01:27 -0700, a ecrit:
> While speech-dispatcher itself has no facility a far as I can tell to
> communicate through serial ports, something like cat could be used to
> send a text of string to the serial port for the synthesizer to
> speak. This is crude, and there is no way to interrupt speech until it
> completes.
> 
> An even better approach is to use
> /sys/accessibility/speakup/synth_direct for the speech output. This
> would use speakup settings in use for the synthesizer. The problem
> with this is the same as with the cat command; no way to interrupt
> speech,

Indeed. But there is another approach, which was made for this: using
/dev/synth. For now that file only supports writing to it to get
text emitted, but ioctls can be defined to drive it, such as setting
pitch etc. in a portable way across synthesizers (speakup will handle
these details), but also interrupting. That all happens in speakup's
devsynth.c and can be a relatively easy task for kernel hacking
beginners.

Samuel